Heat pumps are mechanical machines that move heat energy from a first environment to a second environment and also in reverse. Heat pumps use a vapor-compression cycle and an intermediate fluid (i.e., refrigerant). The refrigerant absorbs heat as it vaporizes in an evaporator and releases heat when it is condenses in a condenser.
An important component of the heat pump is a reversing valve, which allows the flow direction of the refrigerant to be changed such that heat can be pumped between two environments in either direction. In particular, a heat pump can bring heat into an occupied space or can remove heat from it. In a cooling mode, the heat pump uses an evaporator to absorb heat from inside the occupied space and rejects the heat to the outside through the condenser. In a heating mode, the heat pump absorbs heat from the outside through the condenser and moves the heat to the occupied space through the evaporator.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.